JPH04139363A - Hydrogen occlusion heat pump - Google Patents

Abstract

PURPOSE:To prevent variation in a heat transfer capacity by thermally separating at least one of a heat absorption side heat exchanger and a heat radiation side heat exchanger from both hydrogen occlusion heat exchanger pair during a heat transfer capacity decreasing period due to switching of a hydrogen flowing direction between the pair of the hydrogen occlusion exchangers. CONSTITUTION:If temperature of a hydrogen occlusion heat exchanger 2 is higher than that of a hydrogen occlusion heat exchanger 1, two-way valves 61, 63, 66, 68 are opened, and two-way valves 62, 64, 65, 67 are closed. Accordingly, a brine circulation pump 7 circulates low temperature brine through the exchanger 1, a heat absorption side heat exchanger 4, a heat accumulator 9a, and a brine circulation pump 8 circulates high temperature brine through the exchanger 2, a heat radiation side heat exchanger 5, and a heat accumulator 9b. If the temperature of the exchanger 2 is lower than that of the exchanger 1, the valves 61, 63, 66, 68 are closed, and the valves 62, 64, 65, 67 are opened. Accordingly, the pump 7 circulates the low temperature brine through the exchanger 2, the exchanger 4, and the accumulator 9a, and the pump 8 circulates the high temperature brine through the exchanger 1, the exchanger 5 and the accumulator 9b.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a hydrogen storage heat pump with little variation in heat transport capacity.

[Prior Art] JP-A-62-194164 discloses a pair of hydrogen storage heat exchangers that have a hydrogen storage alloy and exchange heat with air, and a compressor and a four-way valve that allows hydrogen to be transferred between the exchangers. Disclosed is a hydrogen storage heat pump type air conditioner comprising a hydrogen pressure-feeding pipe section that reciprocates hydrogen.

In this device, the hydrogen exchanger repeatedly absorbs and radiates heat through the hydrogen reciprocation, and as a result, one of the low-temperature air and the high-temperature air coming out of the Ganzen exchanger is supplied to the campus, and the other is discharged into the atmosphere. .

JP-A No. 62-294868 discloses a hydrogen storage heat pump in which two pairs of hydrogen storage heat exchangers each having a hydrogen storage alloy are provided, and each pair of hydrogen storage heat exchangers reciprocates hydrogen at different phases using a compressor. Disclose. In this device, brine is circulated between the two hydrogen storage heat exchangers on the hydrogen release side and the heat exchanger on the heat absorption side, and the brine is circulated between the two hydrogen storage heat exchangers on the hydrogen absorption side and the heat exchanger on the heat radiation side. Brine is circulated to and from the exchanger to provide heat transfer.

In this device, the heat transport peaks of the two pairs of hydrogen storage heat exchangers have a phase difference (time difference), so fluctuations in the overall heat transport waveform can be suppressed.

[Problems to be Solved by the Invention] However, in the hydrogen storage heat pump having the pair of hydrogen storage heat exchangers described above, each time the hydrogen and air are switched, the heat transport capacity, that is, the heat absorption and heat dissipation capacity decreases due to the influence of the heat capacity of the hydrogen system. As a result, there is a problem that the heat transport capacity fluctuates greatly.

On the other hand, although the above-mentioned hydrogen storage heat pump with two pairs of hydrogen storage heat exchangers can reduce fluctuations in heat transport capacity, it requires additional hydrogen storage heat exchangers and the structure becomes more complicated, making it impractical. There is a problem of lack.

The present invention has been made in view of these problems, and an object to be solved is to provide a hydrogen storage heat pump that can suppress fluctuations in heat transport capacity while avoiding complication of the configuration as much as possible.

[Means for Solving the Problems 1] The hydrogen storage heat pump of the present invention includes a pair of hydrogen storage heat exchangers having a hydrogen storage alloy, and a hydrogen pressure transmission pipe section for reciprocating hydrogen between the two hydrogen storage heat exchangers. , an endothermic piping section that circulates a thermal fluid between the endothermic side heat exchanger and the endothermic side heat exchanger, the hydrogen storage heat exchanger and the endothermic side heat exchanger on the hydrogen release side, and the hydrogen absorbing side heat exchanger. A heat radiation piping section that circulates thermal fluid between the heat storage heat exchanger and the heat radiation side heat exchanger is provided, and during a period when the heat transport capacity is reduced due to switching of the direction of hydrogen flow between the two hydrogen storage heat exchangers, the heat absorption piping part is provided. The present invention is characterized in that a separation means is provided for separating at least one of the side heat exchanger and the heat radiation side heat exchanger from both of the hydrogen storage heat exchanger pair.

[Function] In the hydrogen storage heat pump of the present invention, the hydrogen pressure feed pipe section reciprocates hydrogen between the pair of hydrogen storage heat exchangers by switching the hydrogen flow path. A hydrogen storage heat exchanger that absorbs hydrogen radiates heat, and a hydrogen storage heat exchanger that releases hydrogen absorbs heat. The endothermic side heat exchanger absorbs heat from the object of heat absorption, and the endothermic piping section transports heat from the endothermic side heat exchanger to the hydrogen storage heat exchanger on the hydrogen release side. The heat radiation piping section transports heat from the hydrogen storage heat exchanger on the hydrogen absorption side to the heat radiation side heat exchanger, and the heat radiation side heat exchanger radiates heat to the heat radiation target.

In particular, the separation means that is a feature of the present invention is such that during a period when the heat transport capacity decreases due to switching of the hydrogen flow direction between both hydrogen storage heat exchangers, at least one of the heat absorption side heat exchanger and the heat radiation side heat exchanger is Thermal separation from both sides of the exchanger pair.

In this way, after a certain amount of operation time has elapsed, the endothermic side heat exchanger and endothermic piping section containing the thermal fluid are cooled to a certain average temperature range, and the heat radiating side heat exchanger and the heat radiating piping section are cooled to a certain average temperature. Because it is heated within this range, it absorbs or radiates heat by its own heat capacity. Then, after a certain period of time has elapsed after switching the direction of hydrogen flow, when the hydrogen storage heat exchanger that absorbs hydrogen reaches a sufficiently high temperature and the hydrogen storage heat exchanger that releases hydrogen becomes sufficiently low, the separation means releases the separation. As a result, heat transport is restarted individually from both hydrogen storage heat exchangers to the heat absorption side heat exchanger and the heat radiation side heat exchanger.

Example 1 (Example 1) An example of the hydrogen storage heat pump of the present invention will be described with reference to FIG.

This device has a pair of hydrogen storage heat exchangers 1.2 filled with hydrogen storage alloy.
Each has a closed container (not shown) filled with hydrogen storage alloy (MmNis) powder and equipped with a ventilation hole through which hydrogen gas can enter and exit. A pipe (not shown) through which brine (thermal fluid in the present invention) flows is wrapped around this closed container, and the hydrogen storage heat exchanger 1.2 is connected to the compressor 3.
and are connected by hydrogen piping so that hydrogen can be reciprocated.

That is, the suction port of the compressor 3 and the hydrogen storage heat exchanger 1.2
and are individually connected via a two-way valve 3L32. Further, the discharge port of the compressor 1130 and the hydrogen storage heat exchanger 1.2 are individually connected via two-way valves 33,34. The compressor @3, the two-way valves 31 to 34, and the hydrogen pipes connecting them constitute the water cable pressure feed pipe section in the present invention.

One end of the pipe wrapped around the hydrogen storage heat exchanger 1 described above is connected to the brine inlet of the heat absorption side heat exchanger 4 and the heat radiation side heat exchanger 5 via the piping 1a and the two-way valves 61 and 62, The other end of the pipe is connected to the outlet of a brine circulation pump 7.8 via a pipe 1b and a two-way valve 63.64.

Similarly, one end of the pipe wrapped around the hydrogen storage heat exchanger 2 is connected to the brine inlet of the heat absorption side heat exchanger 4 and the heat radiation side heat exchanger 5 via the piping 2a and two-way valves 65 and 66. , the other end of the pipe is connected to the outlet of the brine circulation pump 7.8 via the pipe 2b and two-way valves 67, 68.

The suction port of the brine circulation pump 7 is connected to the brine outlet of the heat absorption side heat exchanger 4 via the heat storage device 9a, and the suction port of the brine circulation pump 8 is connected to the heat radiation side heat exchanger 5 via the heat storage device 9b. connected to the brine outlet.

Here, the two-way valves 61, 63, 65, 67 and the brine piping between them and the endothermic side heat exchanger 4 constitute the endothermic piping section in the present invention, and similarly, the two-way valves 62, 64, . 66.
68 and the brine piping between them and the heat radiation side heat exchanger 5 constitute a heat radiation piping section in the present invention. In this case, the cooling mode is set, and the endothermic side heat exchanger 4 is on the indoor side,
The heat radiation side heat exchanger 5 is placed on the outdoor side, but during heating, by switching the three-way valves 61 to 68, the heat absorption side heat exchanger 4 on the indoor side can be easily changed to the heat radiation side heat exchanger 4 on the outdoor side. 5
Of course, it is also possible to operate it as an endothermic heat exchanger.

Further, the brine pipes 1a and 1b are connected through a bypass valve 6a to bypass the hydrogen storage heat exchanger 1, and the brine pipes 2a and 2b are connected through a bypass valve 6b to bypass the hydrogen storage heat exchanger 2. There is. Furthermore, the brine pipe 1b is provided with a three-way valve 6C on the downstream side of the bypass valve 6a and on the upstream side of the hydrogen endothermic exchanger 1, and similarly, the brine pipe 2b is provided with a three-way valve 6C on the downstream side of the bypass valve 6b and on the upstream side of the hydrogen endothermic exchanger 2. Three-way valve 6 on the upstream side
d is provided.

These bypass valves 5a, 5b and two-way valve 6C16d constitute separation means in the present invention.

Furthermore, a temperature sensor 11 is provided near the hydrogen inlet/outlet of the hydrogen storage heat exchanger 1, and a temperature sensor 12 is similarly provided near the hydrogen inlet/outlet of the hydrogen storage heat exchanger 2. The output signals V11 and V1 of these temperature sensors 11 and 12 are
2 is sent to the circuits shown in FIGS. 2 and 3, and the two-way valves 61 to 6
8 and bypass valves 6a, 6b are switched.

Note that the heat accumulators 9a and 9b are made up of tanks that store brine.

Next, the operation of this device will be explained.

First, we will explain hydrogen round trip. Initially, hydrogen is stored in the hydrogen storage heat exchanger 1, and the two-way valves 31 and 34 are opened.
Two-way valves 32,33 are in the closed state.

In such a state, when hydrogen gas is pressure-fed from the hydrogen storage heat exchanger 1 to the hydrogen storage heat exchanger 2 by the compression@3 operation, the hydrogen storage heat exchanger 1 that releases hydrogen absorbs heat from the brine and absorbs hydrogen. The hydrogen storage heat exchanger 2 radiates heat to the brine.

After the hydrogen storage heat exchanger 1 releases hydrogen gas for a predetermined period of time, the compressor 3 is stopped, the two-way valves 31 and 32 are opened, and the three-way valve 3 is opened.
3. If 34 is switched to the closed state, hydrogen gas will flow from the hydrogen storage heat exchanger 2 to the hydrogen storage heat exchanger 1 because the hydrogen gas pressure in the hydrogen storage heat exchanger 2 that stores a large amount of hydrogen is high. As a result, the hydrogen storage heat exchanger 2 absorbs heat from the brine, and the hydrogen storage heat exchanger 1, which absorbs hydrogen, radiates heat to the brine.

When the pressure difference in the hydrogen storage heat exchanger 1.2 falls below a certain level, the two-way valve 31.34 is roughly closed, and the two-way valve 32.33 is closed.
The compressor 3 is operated by switching to the open state. As a result, hydrogen gas is continuously fed under pressure from the hydrogen storage heat exchanger 2 to the hydrogen storage heat exchanger 1, and the hydrogen storage heat exchanger 2 releases hydrogen.
absorbs heat from the brine, and the hydrogen storage heat exchanger 1 that absorbs hydrogen radiates heat to the brine.

After the hydrogen storage heat exchanger 2 releases hydrogen gas for a predetermined period of time, the compression l113 is stopped, and the three-way valves 31 and 32 are opened again.
If the two-way valves 33 and 34 are switched to the open state, the hydrogen gas pressure in the hydrogen storage heat exchanger 1 that stores a large amount of hydrogen is high, so hydrogen is transferred from the hydrogen storage heat exchanger 1 to the hydrogen storage heat exchanger 2. The gas flows, so that the hydrogen storage heat exchanger 1 absorbs heat from the brine, and the hydrogen storage heat exchanger 2, which absorbs hydrogen, radiates heat to the brine.

In this way, one round trip (one cycle) of the hydrogen gas is completed, and by repeating this cycle thereafter, the brine coming out of the hydrogen storage heat exchanger 1 is heated and cooled at regular intervals.

The switching of the two-way valves 31 to 34 and the intermittent operation of the compressor 3 in this cycle operation can all be periodically controlled by a timer at regular intervals, so further explanation will be omitted.

Hydrogen storage heat exchanger 1 is installed for heat capacity of hydrogen piping system, etc.
．． The temperature at point 2 is, for example, as shown in FIG. 4 (a>).

Next, the operations of the heat absorption piping section that always circulates cooling brine to the heat exchanger 4 on the heat absorption side and the heat radiation piping section that always circulates heating brine to the heat exchanger 5 on the heat radiation side will be described.

The output signals V11 and v12 of the temperature sensors 11 and 12 are the second
is sent to the comparator 100 shown in the figure, and the comparator 1
00 is when Vll is larger than Vl2 (that is, when hydrogen storage heat exchanger 1 is higher temperature than hydrogen storage heat exchanger 2)
It becomes a low level when v12 is larger than Vll (that is, when the hydrogen storage heat exchanger 2 is at a higher temperature than the hydrogen storage heat exchanger 1). Therefore, transistors 101-104 turn on when Vl2 is larger;
Conversely, due to the inversion of the output of inverter 105, transistor 1
06 to 109 are turned on when Vll is larger.

As a result, when the temperature of the hydrogen storage heat exchanger 2 is higher than the temperature of the hydrogen storage heat exchanger 1 (Vl 2 > Vll), the two-way valve 61.63.66.68, which is a solenoid valve, opens and the two-way valve 61.63.66.68 opens. Close valves 62, 64, 65, 67. Therefore,
The brine circulation pump 7 circulates low-temperature brine through the hydrogen storage heat exchanger 1, the heat absorption side heat exchanger 4, and the heat storage device 9a, and the brine circulation pump 8 circulates the low temperature brine through the hydrogen storage heat exchanger 2, the heat radiation side heat exchanger 5, and the heat storage device. 9b circulate hot brine.

Also, the temperature of the hydrogen storage heat exchanger 2 or the temperature of the hydrogen storage heat exchanger 1
(Vll>Vl2), the two-way valve 61
．． 63.66.68 are closed, two-way valves 62.64.65.
67 opens. Therefore, the brine circulation pump 7 circulates low-temperature brine to the hydrogen storage heat exchanger 2, the heat absorption side heat exchanger 4, and the heat storage device 9a, and the brine circulation pump 8 circulates the low temperature brine to the hydrogen storage heat exchanger 1, the heat radiation side heat exchanger 5, High temperature brine is circulated through the heat storage device 9b.

As a result, the heat exchanger 4 on the endothermic side is always supplied with low-temperature brine, and the heat exchanger 5 on the heat-radiating side is always supplied with high-temperature brine.

The heat storage device 9a absorbs heat from the low-temperature brine during the above-described operation switching time period, and radiates heat to the low-temperature brine during a time period away from the switching time. Similarly, the heat accumulator 9b radiates heat to the high temperature brine during the operation switching time period described above, and absorbs heat from the high temperature brine during a time period away from the switching time.As a result of the above, fluctuations in the brine temperature are suppressed. Therefore, fluctuations in the cooling capacity of the endothermic side heat exchanger (indoor unit) 4 (that is, the temperature of the low-temperature brine) are reduced.

Next, the switching operation of the bypass valves 6a, 6b and the two-way valve 6C16d will be explained using the control circuit shown in FIG.

A binary signal output from comparator 100 (see FIG. 2) is input to mono multivibrator 110, and a binary signal output from inverter 105 (see FIG. 2) is input to mono multivibrator 111. As a result, the mono multivibrator 110 is at a high level for a certain period of time from the time when Vl2 becomes larger than Vll, and the mono multivibrator 111 is at a high level for a certain period of time from the time when Vll becomes larger than Vl2. Mono multivibrator 110.111 drives driver transistor 113.114 via OR circuit 112. That is, when mono-multivibrator 110.111 becomes high level (that is, only for a certain period of time after Vll becomes higher temperature than V12 and from the time V12 becomes higher temperature than Vll, respectively), driver transistor 113.
114 opens bypass valves 5a and 6b, which are solenoid valves, respectively, and driver transistors 115.11
6 closes the two-way valves 5c and 5d, which are solenoid valves.

As a result, the brine passes through the bypass valves 6a and 6b for a certain period of time immediately after switching the hydrogen flow direction (a period when the temperature of the hydrogen storage heat exchanger 1.2 is approximately the same), so the hydrogen storage heat exchanger 1.2 passes through the bypass valves 6a and 6b. No brine flows through hydrogen storage heat exchanger 1.2, and as a result, endothermic heat exchanger 4 is heated by hydrogen storage heat exchanger 1.2, and exothermic heat exchanger 5 is not cooled.

FIG. 4(b) shows an example of temperature fluctuation of low-temperature brine when bypass valves 6a and 6b are not provided, and FIG. 4(C)
An example of temperature fluctuation of the low-temperature brine according to this embodiment (when bypass valves 6a and 6b are provided) is shown in FIG.

In the above embodiment, the bypass valves 6a, 6b and the two-way valve 6C16d are closed due to temperature reversal of the hydrogen storage heat exchanger 1.2.
However, the bypass valves 6a, 6b and the two-way valve 6C16d may be controlled before that.

For example, when the two-way valves 31 to 34 and the compressor 3 are operated periodically by a timer, the temperature of the hydrogen storage heat exchanger 1.2 is approximately the same, that is, the bypass valves 6a and 6b are opened, and the three-way valve 6C16d is Since the period during which the bypass valves 6a and 6b and the two-way valve 6C16 should be closed is known in advance,
d may be controlled by a timer in synchronization with the two-way valves 31 to 34 and the compressor 3.

Note that in the above embodiment, hydrogen transport can be carried out by thermal drive instead of mechanical drive by the compressor 3, as before.

[Effects of the Invention] As explained above, in the hydrogen storage heat pump of the present invention, the heat exchanger on the endothermic side and the heat exchanger on the exothermic side are Separation means is provided for separating at least one of the hydrogen storage heat exchangers from both of the pair of hydrogen storage heat exchangers.

Therefore, during the period when the heat transport capacity decreases between the hydrogen storage heat exchanger and at least one of the endothermic side heat exchanger and the heat radiating side heat exchanger due to the switching of the hydrogen flow direction, the endothermic side heat is cooled to within the average temperature range. It is possible to prevent the exchanger and endothermic piping (including the thermal fluid) from cooling the high temperature hydrogen storage heat exchanger. Alternatively, it is possible to prevent the radiation-side heat exchanger and the radiation piping section (including the thermal fluid) heated to within the average temperature range from heating the low-temperature hydrogen storage heat exchanger.

As a result, it is possible to prevent a decrease in the heat transport capacity from the hydrogen storage heat exchanger to at least one of the heat absorption side heat exchanger and the heat radiation side heat exchanger, and also suppress fluctuations in the heat transport capacity with a simple device configuration. be able to.

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing a first embodiment of the present invention, Fig. 2 is a valve control circuit diagram, Fig. 3 is a bypass valve control circuit diagram, and Fig. 4 is a block diagram showing a first embodiment of the present invention.
The figure is a waveform diagram showing changes in the amount of heat absorbed. 1.2...Hydrogen storage heat exchanger 3...Compressor (part of the hydrogen pressure transmission pipeline) 4...Endothermal side heat exchanger 5...Radiation side heat exchanger 6a, 6b...・Bypass valve (separation means) 6C16d・
・-Two-way valve (separation means) 7.8... Pump

Claims (1)

[Scope of Claims] A pair of hydrogen storage heat exchangers having a hydrogen storage alloy, a hydrogen pressure transmission pipe section for reciprocating hydrogen between the two hydrogen storage heat exchangers, an endothermic heat exchanger, and a heat radiation side heat exchanger. an endothermic piping section that circulates thermal fluid between the hydrogen storage heat exchanger on the hydrogen release side and the heat absorption side heat exchanger, and the hydrogen storage heat exchanger and the heat radiation side heat exchanger on the hydrogen absorption side. and a heat dissipation piping section that circulates thermal fluid between the heat exchanger and the heat exchanger during a period when the heat transport capacity is reduced due to switching of the direction of hydrogen flow between the two hydrogen storage heat exchangers. A hydrogen storage heat pump characterized in that a separation means is provided for separating at least one of the hydrogen storage heat exchangers from both of the pair of hydrogen storage heat exchangers.